The oxidation of a single composition of n-butenes or isobutylene to a corresponding oxide have been known.
A process for preparing only 1,3-butadiene with catalyst similar to this invention is previously disclosed in Japanese Pat. Publication No. 26842/1968. For preparing methacrolein, a similar catalysts is used in Japanese Pat. Publication No. 2324/1968. The catalysts used in said Patent are composed of, for example, nickel, cobalt, iron, bismuth, phosphorus and molybdenum. The highest single pass yields in Examples given in the specification is 83% for single pass yield of 1,3-butadiene from butene-1, and is only 37 % for those of methacrolein.
On the other hand, a process for the simultaneous preparation of methacrolein and 1,3-butadiene in the same method as in the present invention have been also disclosed in Japanese Pat. Publication No. 7881/1967. In the specification of this publication, the same process carried out over a catalyst comprised of oxides of V, Bi and Mo, and the highest yields of 67% for methacrolein, but that of only 76% for 1,3-butadiene are obtained.